The present invention relates to a pull-top can and, more particularly, to a pull-top can having an improved lid.
In recent years, as a can containing beverages, beer, any other seafood, or the like, a structure having a lid with a pull-top mechanism capable of easy opening is known.
A conventional pull-top can comprises a body made of stainless steel or aluminum and having an open top and a lid having a pull-top mechanism and caulked at the opening portion of the body. For example, the pull-top mechanism of a beverage can comprises a cut-open portion constituted by a saddle-shaped groove formed by pressing and a pull-tab joined with a pin so as to be in contact with the peripheral surface of the lid. This pull-top mechanism can be opened by bending the lid portion located inside the saddle-shaped cut-open portion toward the body upon raising the pull-tab with a finger. The lid is made of aluminum so that the lid may be easily cut along the saddle-shaped cut-open portion of the pull-top mechanism.
For example, an organic resin film such as a polyethylene terethphalate film is laminated on the inner surface of the body to prevent the contents from directly contacting the body material such as stainless steel or aluminum, thereby preventing degradation of the quality of the contents.
On the other hand, when an organic resin film such as the polyethylene terephthalate film is laminated on the inner surface of the lid attached with the pull-top mechanism, the pull-top mechanism can hardly cut the lid because the organic resin film has a high tear (fracture) strength. As a result, the lid cannot practically be opened by the pull-top mechanism.
Under the above circumstances, for example, an epoxy-phenol resin thin film having a thickness on the order of submicrons is formed on the inner surface of the lid by baking finish, so that the contents can be protected without coming into contact with aluminum as the lid material and without impairing the opening properties of the pull-top mechanism.
Baking finish on the inner surface of the lid with the epoxy-phenol resin thin film results in a poor working environment and increases the running cost because a very large amount of water is required after coating. In addition, the resin thin film formed on the inner surface of the lid by baking finish provides poorer protection for contents than the organic resin film laminated on the inner surface of the body.